Summary
Workarounds
The patch can be applied manually to templates/changesdoc.vm in the deployed WAR.
Attribution
XWiki thanks Mike Cole @mikecole-mg for discovering and reporting this vulnerability.
Impact
A reflected cross-site scripting vulnerability (XSS) in the compare view between revisions of a page allows executing JavaScript code in the user's browser. If the current user is an admin, this can not only affect the current user but also the confidentiality, integrity and availability of the whole XWiki instance.
CVE-2026-40105 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (16.10.16, 17.4.8, 17.10.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The problem has been patched by properly escaping the URL parameters.
Frequently Asked Questions
- What is CVE-2026-40105? CVE-2026-40105 is a medium-severity security vulnerability in org.xwiki.platform:xwiki-platform-web-templates (maven), affecting versions >= 10.4-rc-1, < 16.10.16. It is fixed in 16.10.16, 17.4.8, 17.10.1.
- How severe is CVE-2026-40105? CVE-2026-40105 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.xwiki.platform:xwiki-platform-web-templates are affected by CVE-2026-40105? org.xwiki.platform:xwiki-platform-web-templates (maven) versions >= 10.4-rc-1, < 16.10.16 is affected.
- Is there a fix for CVE-2026-40105? Yes. CVE-2026-40105 is fixed in 16.10.16, 17.4.8, 17.10.1. Upgrade to this version or later.
- Is CVE-2026-40105 exploitable, and should I be worried? Whether CVE-2026-40105 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-40105 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-40105?
- Upgrade
org.xwiki.platform:xwiki-platform-web-templatesto 16.10.16 or later - Upgrade
org.xwiki.platform:xwiki-platform-web-templatesto 17.4.8 or later - Upgrade
org.xwiki.platform:xwiki-platform-web-templatesto 17.10.1 or later
- Upgrade